Apache Tomcat Replay Auth via EncryptionInterceptor v8.5-11.x
CVE-2026-55955 Published on June 29, 2026
Apache Tomcat: EncryptInterceptor not protected against replay attacks
Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109.
Users are recommended to upgrade to version 11.0.23, 10.1.56, 9.0.119, which fixes the issue.
Vulnerability Analysis
CVE-2026-55955 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-55955 has been classified to as an authentification vulnerability or weakness.
Products Associated with CVE-2026-55955
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Affected Versions
Apache Software Foundation Apache Tomcat:- Version 11.0.0-M1, <= 11.0.22 is affected.
- Version 10.1.0-M1, <= 10.1.55 is affected.
- Version 9.0.13, <= 9.0.118 is affected.
- Version 8.5.38, <= 8.5.100 is affected.
- Version 7.0.100, <= 7.0.109 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.